在外部存储中保存图像

Question

我的问题是，当我点击图片时，它显示已保存的消息但照片不会被保存。我还允许访问外部存储 WRITE_EXTERNAL_STORAGE

    public void onClick(View v) {
    if(isExternalStorageWriteable()) {
        FileOutputStream outputStream;
        Bitmap bitmap = BitmapFactory.decodeResource(getResources(),
                R.drawable.img3);
        File file = new File(Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_DOCUMENTS), "MyImage.png");
        try {
                outputStream = new FileOutputStream(file);
            bitmap.compress(Bitmap.CompressFormat.PNG, 100, outputStream);
            outputStream.flush();
            outputStream.close();
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
        Toast.makeText(this,"Pic Created :  "+file,Toast.LENGTH_SHORT)
                .show();
    } else {
            Toast.makeText(this,"SDCard Not is Ready",Toast.LENGTH_SHORT)
                    .show(); } }
public boolean isExternalStorageWriteable()
{
    String state = Environment.getExternalStorageState();
    return Environment.MEDIA_MOUNTED.equals(state); }

Answer 1

“我还允许访问清单中的外部存储 WRITE_EXTERNAL_STORAGE”，或者您在运行时要求获得许可？

我猜您只有在 Android 版本 >= 23 (6.0) 的设备上才会遇到这个问题。 你应该在做之前检查你是否有权限在外部存储中写入，如果你应该请求权限：

ContextCompat.checkSelfPermission(thisActivity, Manifest.permission. WRITE_EXTERNAL_STORAGE);

ActivityCompat.requestPermissions(thisActivity, new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE}, MY_PERMISSIONS_REQUEST_WRITE_EXTERNAL_STORAGE);

https://developer.android.com/training/permissions/requesting.html

如果获得许可，检查堆栈跟踪并将其发布在这里，确保“Pic Created”toast 应保留在块末尾的 try-catch 内，而在 catch 块内，您将不得不启动否定 Toast。